Table 1.

Neuron numbers across each age group suggest a reduction of neurons in autism across all amygdala subregions examined

Region	Age group	No. of neuronsa		F tests,b partial η2
		ASD	NT
Total amygdala	Child	12.40 (1.18)c,**	11.46 (1.29)	(All) F(2,41) = 5.69, P = 0.007, η2 = 0.22
	Adolescent	11.32 (0.91)	12.22 (0.75)	(− Girls) F(2,33) = 4.35, P = 0.021
	Adult	10.64 (1.67)d,*	12.75 (1.58)	(− Seizure) F(2,31) = 8.54, P = 0.001
Lateral	Child	3.74 (0.45)	3.81 (0.52)	(All) F(1,39) = 5.24, P = 0.028e, η2 = 0.12
	Adolescent	3.46 (0.46)	3.82 (0.60)	(− Girls) F(1,32) = 6.91, P = 0.013e
	Adult	3.29 (0.61)d,**	3.91 (0.32)	(− Seizure) F(1,29) = 6.90, P = 0.014e
Basal	Child	3.14 (0.54)c,*,f,*	2.62 (0.27)	(All) F(2,41) = 7.13, P = 0.002, η2 = 0.26
	Adolescent	3.00 (0.36)	3.00 (0.36)	(− Girls) F(2,33) = 4.44, P = 0.020
	Adult	2.65 (0.52)d,**	3.42 (0.70)g,**	(− Seizure) F(2,31) = 5.08, P = 0.012
Accessory basal	Child	1.21 (0.16)c,**	1.07 (0.14)	(All) F(2,41) = 6.85, P = 0.003, η2 = 0.25
	Adolescent	1.11 (0.21)	1.20 (0.27)	(− Girls) F(2,33) = 7.23, P = 0.002
	Adult	0.94 (0.20)d,***	1.25 (0.14)g,*	(− Seizure) F(2,31) = 6.85, P = 0.003
Central	Child	0.39 (0.04)c,*,f,*	0.31 (0.08)	(All) F(2,39) = 4.23, P = 0.022, η2 = 0.18
	Adolescent	0.36 (0.07)	0.38 (0.01)	(− Girls) F(2,31) = 7.58, P = 0.002
	Adult	0.32 (0.05)	0.36 (0.04)	(− Seizure) F(2,30) = 3.59, P = 0.040

^aMean (SD) number of neurons in millions.

^bF tests reveal a significant interaction between age category and diagnosis among all regions, except for the lateral nucleus, which showed a main effect of diagnosis. Excluding girls (− Girls) or individuals with seizure disorder (− Seizure) did not change the pattern of results.

^cChild ASD > adult ASD.

^**P < 0.01. Post hoc results regarding adolescents are omitted for clarity.

^dAdult ASD < adult NT.

^*P < 0.05.

^eMain effect of diagnosis on F test; all others are age group × diagnosis interactions.

^fPost hoc: child ASD > child NT.

^gChild NT < adult NT.

^***P < 0.001.